Metacarpal Muscles

The lumbricales are absent, unless we regard as such the muscular bundles which arise on the deep flexor and are inserted into the superficial flexor tendon at the carpus.

The interosseus medius or suspensory ligament is somewhat more muscular than in the horse; indeed, in the young subject it may be almost entirely fleshy. Its arrangement is somewhat complex. Single at its origin, it detaches about the middle of the metacarpus a band which joins the tendon of the superficial flexor and concurs near the fetlock in the formation of the ring for the deep flexor tendon. A little lower down it divides into three and then into five branches. The lateral branches (two pairs) are attached to the corresponding sesamoids and tendons of the proper extensors, while the middle branch passes through the sulcus at the distal end of the metacarpus and bifurcates, each division fusing with the tendon of the corresponding proper extensor.

It is to be noted that the fascia on the posterior face of the metacarpus and digit is very thick. It is continuous above with the ligamentum carpi transversum, and is attached on either side to the metacarpal bone. At the fetlock it forms the fibrous basis for the small claws, and below this it detaches two strong bands which diverge to be inserted into the second and third phalanges, blending with the lateral ligaments.

The Muscles of the Pelvic Limb